You mean all standard were derivatized together ?
Do you get as clean results with natural hemp type samples ?
I feel a little bit better about that impulse purchase on a speed vac centrifuge with cold trap 
The remains of the derivatization agent? Iām not entirely clear what youāre referring to here.
I donāt have a fume hood per se, I do have a PAR (that looks wrong to me, maybe its right) and a fan that on full speed will evac the room in under a minute. Itās an area I need to improve but it hasnāt been a big priority considering the effort required.
My current procedure for anything nasty is to put on the PAR and other PPE, turn the fan on until I can feel the air in the room moving past me then turn on the PAR and do whatever.
I guess my question is two fold now: is that sufficient precaution for messing with the derivatization agent (or, perhaps in general considering the environment)? Would the cold trap in the centrifuge capture all the nastiness, and if so, assuming it should be discarded and the cold trap cleaned?
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When doing derivatization, one better use an excess of agent, pure (using at as a solvent), even with an addition of little bit pyridine (usually less than the agent itself, havenāt try to compare yet). Once you are done, one can inject that directly in the machine, or better be removed to the max, to avoid fooling it.
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I canāt tell you how risky it is. Depends if it occasional or not alsoā¦ you donāt use that much ag a time, so a simple room temp trap and a pipe going to the ventilztion should be enough. You can just buble it in water if you are concerned with environmental issues.
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Would I be correct assuming the derivative method above is different than the one outlined by Sri in their acid test videos? I ask only to understand if that video was maybe a little lackadaisical or if the MSTFA is safer overall?
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Indeed
Yes we had mix of 5 cannabinoids @ 1mg/mL (CBD, CBDa, THCa, d9-THC, CBG) and another standard of d8-THC @ 500Āµg/mL and a CBN @ 500Āµg/mL. These are all pipette into a single vial, dried down under N2, and then derivatized.
As far as real world samples, yes they look quite clean, obviously not as clean as pure standards but quite high resolution overall.
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Who do you get your standards from?
I have had no problem with Cayman, Absolute Standards, or Restek. A great resource is this:
They have many vendors so it is easy to browse and price compare, just be wary of the concentration and overall volume. Make sure any any acidic cannabinoids you purchase are in ACN, likely you will not find any that are not anymore but in the early days they were shipped in MeOH which decarbs over time.
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Thank you! I was looking at Restek and Iāll certainly price shop before pulling the trigger either way.
From my understanding with a GC-FID, testing the acid forms only requires making derivative of the normal standard forms (as the acid forms decarb during the sample process), is that correct?
Yes, the inlet of the GC is quite hot as it needs to volatize the sample into a gaseous phase. If we were to simply inject pure CBDa or CBGa the cannabinoids would decarb in the inlet and co-elute with their neutral counterparts. By derivatizing the sample, for example with TMS, we are replacing the active hydrogens with trimethylsilyl groups. Once those active hydrogens are replaced the acidic cannabinoids are now thermally stable as we have blocked the mechanism for them to decarb.
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Would you have a brief explanation for why you use the BMSTFA + TMS versus plain MSTFA? Iām curious if theres an advantage worth any risks over using plain MSTFA (which by all accounts appears reasonably safe to handle), being that Iām in a small home environment
Simply put TMCS acts as a catalyst which helps overcome steric hindrance issues.
You may be able to get the same results with MSTFA, it may just take more time. I have not personally used this agent but there is plenty of literature on the subject. It does not seem like you have much of a choice considering you are not working in a fume hood (please be careful, you only have one set of lungs/eyes).
The best advice I can give is to try it out and run some derivatization efficiency studies with MSTFA to ensure you are going to completion, otherwise you will run into issues with reproducibility and accuracy.
Here is a good write up on the differences w/ and w/o TCMS: https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Aldrich/General_Information/bsa_tmcs.pdf
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Much appreciated! Iāll read a bit more on it. Seems like starting with MSTFA may be easier but Iāll research some more. I donāt have a fume hood as you mention, I do have an explosion proof fan and a PAR I use anytime Iām messing with something volatile (or stinky). Iām not sure if this is sufficient, but Iāll see what more I can find out and make a determination from there.
Thank you again @Chaboes!
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Sorry, I think I did not answer your question completely as I only described the effects of the addition of TCMS. I may be mistaken but the difference between MSTFA and BSTFA is somewhat minor (at least for FID purposes). BSTFA has a bit of an easier time with sterically hindered groups, and MSTFA will make slightly more volatile derivatives. These differences are more noticeable in MS but I do not think they will have a large difference for FID.
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Thatās okay, some of it is lost on me anyway 
Thatās why I like to read and come back to it. At the end of the day I do want good clean separations (that OCD man), but only if it is safe to do so.
I donāt technically need to be able to discern them, but I want to know how to
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Pages 7+ of this doc will be super helpful for you as well, goes over the main derivatizing agents and their target groups.
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Another good resource thank you again! Iām seeing a lot of mention of hydrocarbons as the solvent; are you using a hydrocarbon solvent? May be another āproā in MSTFA column for me as acetone is cheap and safe to handle
Non-polar solvents work great, all you want to avoid is anything with active hydrogens (like alcohols -OH) as they consume the derivatizing agent. Acetone should work great (get ACS grade+).
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Iām about to purchase the standards from Restek, before I do Iām wondering if there any any opinions on purchasing the blended (CBD/d9/CBN) cannabinoids versus them individually. Is there a benefit to one or the other?
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